diff --git a/htdocs/langs/en_US/admin.lang b/htdocs/langs/en_US/admin.lang
index a529bdaec94..6505aef89d8 100644
--- a/htdocs/langs/en_US/admin.lang
+++ b/htdocs/langs/en_US/admin.lang
@@ -974,7 +974,7 @@ MAIN_MAX_DECIMALS_UNIT=Max decimals for unit prices
 MAIN_MAX_DECIMALS_TOT=Max decimals for total prices
 MAIN_MAX_DECIMALS_SHOWN=Max decimals for prices shown on screen (Add <b>...</b> after this number if you want to see <b>...</b> when number is truncated when shown on screen)
 MAIN_DISABLE_PDF_COMPRESSION=Use PDF compression for generated PDF files.
-MAIN_ROUNDING_RULE_TOT= Size of rounding range (for rare countries where rounding is done on something else than base 10)
+MAIN_ROUNDING_RULE_TOT=Step of rounding range (for countries where rounding is done on something else than base 10. For example, put 0.05 if rounding is done by 0.05 steps)
 UnitPriceOfProduct=Net unit price of a product
 TotalPriceAfterRounding=Total price (net/vat/incl tax) after rounding
 ParameterActiveForNextInputOnly=Parameter effective for next input only